1970 Duster Fuel System Upgrade/Updates

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KOZ45

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My Duster was a 340 factory car, now with a 440

I removed the stock mechanical pump and installed an Edelbrock # 1723 Performer RPM Street Fuel mechanical pump

This pump uses 3/8" IN / 3/8" OUT fittings and is rated at 110 GPH

The tank looks old/factory so I plan on dropping it and installing a new tank

I also believe the fuel lines are stock, so they look to be 5/16"

When dropping the tank, would it also be a good idea to replace the lines from the tank to the pump, with 3/8" lines?

What about the stock fuel sending unit? Is there difference ones/sizes? I was hoping there was a 5/16" and 3/8" size option?
 
I did my daughters 70 duster and I think I put 3/8 lines and sender in it ,been 8 years tho.
 
Is it best to use pre-formed 3/8" metal lines or is anyone using a roll of rubber 3/8" fuel hose?
 
I used pre made lines, I think from fine lines or another company like I said I just don't remember
 
I wouldn't. Only where it needs it by the pump and sender. I used 3/8 aluminium but I've been told that's not great. Probably steel lines would be best. (I'm no expert)
 
I used this on both my Darts. I used a brake flaring tool to put a (small) bubble on the ends so the line clamps can't blow off.
A-Team Performance 3/8" Diameter 25' Aluminum Coiled Tubing Fuel Line | eBay
images?q=tbn:ANd9GcT-1vxK05gFgAooabhQOhtqp3D00MPZjy2obw&usqp=CAU.jpg
 
25' roll of rubber 3/8" fuel hose is $25 shipped

Seems like this would be very easy to route and work with.......if its a good idea?
 
Just know that if you try to attend any sanctioned NHRA event or any track that is NHRA backed. You will "NOT" be allowed to even make a single run down the track. You can only have 12" inches total of rubber line. Then there are rules as to where the line can and can not run. I have run aluminum line for years and have never had a problem that I didn't create myself.
 
25' roll of rubber 3/8" fuel hose is $25 shipped

Seems like this would be very easy to route and work with.......if its a good idea?
Terrible idea. Rubber fails, steel generally doesn't. Also, you would never pass tech at a dragstip, if you ever want to race your car. 12" maximum rubber line. Heck, i have braided stainless line, rubber inside, that has failed/leaks, and that is legal at the dragstrip. I use nothing but teflon lines now. They last ten times longer than braided stainless rubber.
In my opinion, 3/8 steel would be best, but i have heard of some very fast cars still using factory 5/16. A good fuel pump is the first requirement. In your case, with a new tank, i would get a 3/8 pickup in the tank, and just use the electric pump and stock lines.
 
Inline tube. Brake and fuel lines. See if you can find someone to carefully remove the 5/16 pick-up tube from your stock sending unit and install a 3/8". The new sending units don't work well with your gauges.
Maybe send you old pick-up sender to Instrument Specialties for mod and recondition.
 
25' roll of rubber 3/8" fuel hose is $25 shipped

Seems like this would be very easy to route and work with.......if its a good idea?

This is a TERRIBLE and dangerous idea. This is not something you should even be considering on a car that will be driven on the street or track.

Buy 3/8" lines from Inline Tube or Fine Lines. They unfold pretty easily, they take a little patience to install back along the factory routing because they are a single piece, just like the factory lines and the larger diameter makes some of the clearances tighter. But well worth it. Even running stainless braided hose the whole length is not a good idea IMO, even if it will pass tech.

And yeah, while 3/8" lines are nice if you're under 500 hp it's doubtful you'll actually need them. I put 3/8" stainless lines on my Challenger and my Duster, 3/8" senders too. But it was more in the name of never having to mess with them again in case i made more engine upgrades than something I absolutely needed.
 
So should I not even mess with replacing the 5/16" lines?

Just worry about a new tank?

Summit says 5/16" for 350 hp

What size fuel line do I need?

440 cars came from the factory with 3/8"

A stock 1968 440 motor was 375hp?
 
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So should I not even mess with replacing the 5/16" lines?

Just worry about a new tank?

Summit says 5/16" for 350 hp

What size fuel line do I need?

440 cars came from the factory with 3/8"

A stock 1968 440 motor was 375hp?

Not sure about the 3/8" on 440 cars. Thought that was a hemi thing, but I could be wrong as I don't have any factory 440 cars.

Summit sounds like they're being pretty pessimistic, I know of cars well over 400 hp that didn't have fuel issues with 5/16" lines. I replaced the lines on my cars because of their condition. The factory stuff wasn't stainless, it doesn't last forever. It also gets kinked, dented, etc. The line on my Challenger had been hit with a jack at some point, for example. So it just depends. If the lines are in good condition they're not a "must replace" deal IMO, just blow them out and off you go. But, if I was going to replace them I would probably just use 3/8", it doesn't cost much more, only takes a few more minutes to install (a little harder to unfold and route), but then you know that's taken care of and won't be an issue. And same with the stainless. A little more money, but I know I'm not gonna have to do it again in my lifetime.
 
Comeback 'Cuda Update: Fuel, Vent lines, and Gas Tank Installation - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar techMopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

The 383 and smaller drivetrains only needed the 5/16-inch fuel line from the tank to the fuel pump

On the 440 and 426 Hemi drive line a larger 3/8-inch fuel line was required

I also read that ALL 440 cars got 3/8 fuel lines starting in 1970
 
The surface area ratio of 3/8 diameter to 5/16 diameter is about .141 / .098 or about 44% more

Chevy used 3/8" lines on their small bock 350 motors in the 1970s

I am going to replace the line on my Duster and run 3/8"
 
I am "fairly" certain my 70 440-6 was 3/8 but I could not swear to that
 
If you are going to replace the tank, why wouldn't you replace the 50 year old fuel lines, and replace them with stainless steel lines - they don't cost that much more than plain steel ones.
 
If you are going to replace the tank, why wouldn't you replace the 50 year old fuel lines, and replace them with stainless steel lines - they don't cost that much more than plain steel ones.

I agree, but they are double the price and I don't plan on keeping the car too long
 
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